116 research outputs found

    Apresentação

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    Este atlas nasceu no seio de um projeto de investigação exploratória concedido no âmbito do programa Investigador FCT. O projeto inclui a análise de padrões biogeográficos dos vertebrados terrestres da Europa Ocidental, com especial incidência na Península Ibérica. Em contraste com os restantes grupos taxonómicos e países a estudar, faltava informação sobre a distribuição dos mamíferos em Portugal, a uma escala adequada às análises previstas no projeto. Foi, portanto, necessário compilar e mapear os registos disponíveis de presença de mamíferos no nosso país. Dado o interesse e a utilidade geral deste tipo de dados, decidiu-se partilhar esta compilação sob a forma de um atlas, tornando a informação acessível e utilizável por todos

    Metodologia

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    Este atlas inclui as espécies de mamíferos silvestres com ocorrência documentada em Portugal, tanto em meio marinho como em meio terrestre. Para os mamíferos terrestres, os mapas incluem todo o território continental e insular. Para os mamíferos marinhos, incluem-se quer as regiões costeiras, quer a Zona Económica Exclusiva (ZEE) de Portugal. Não se inclui um capítulo especificamente dedicado à distribuição dos morcegos (ordem Chiroptera), por estes terem sido alvo de um atlas recente ao qual pouco teríamos a acrescentar; no entanto, os dados relativos a este grupo estão incluídos no capítulo “Análises biogeográficas exploratórias“

    Barrier and mechanical properties of clay-reinforced polymeric nanocomposites

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    In this work, clay-based nanocomposites films were prepared by addition of clay-Na+ natural montmorillonite in pectin and hydroxypropyl methylcellulose (HPMC) matrices. Mechanical (tensile strength, elastic modulus, and elongation) and barrier (Water Vapor Permeability (WVP), and Oxygen permeability (O2P)) properties were investigated. From results, it was observed that the WVP and O2P decreased when nanoclay was included into the HPMC and pectin matrix films. Additionally, the incorporation of nanoclay in the films significantly improved the mechanical properties because the reinforcing effect of clay from its high aspect ratio and its enormous surface area. These results are very important in packaging area.CNPqFINEPFAPES

    Conhecer melhor a nossa biodiversidade: o Atlas de Mamíferos de Portugal

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    The Atlas of Mammals of Portugal compiles the most up-to-date and finest-resolution distribution database of Portuguese terrestrial and marine mammals (except bats) across the country (mainland and islands) and its Exclusive Economic Zone. The inclusion of marine mammals, which are often left out of mammal atlases, is of particular relevance in this work, especially given the large extent of the Exclusive Economic Zone of Portugal, which covers a substantial portion of the Eastern North Atlantic. This atlas was developed as part of a research project on vertebrate biogeography in the Iberian Peninsula and Western Europe, and it resulted from a combination of efforts of numerous individuals and entities. Its preparation consisted in the compilation of an unprecedented volume of mammal occurrence records in our country, whose subsequent selection was based on rigorous methods and validation procedures, according to international standards. In this article, we present a brief description of the background that motivated the elaboration of this atlas, the methodology used, the main results of this work, and its limitations. The Atlas of Mammals of Portugal has great potential to become an essential tool for better evaluation of the conservation status of mammal species in Portugal and, consequently, for improving their conservation and management in this country. We also make a call for additional contributions of mammal occurrence data, which can be included in subsequent editions of the Atlas

    The Proterozoic Vazante hypogene zinc silicate district, Minas Gerais, Brazil: a review of the ore system applied to mineral exploration

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    The Proterozoic Vazante zinc silicate district in Minas Gerais, Brazil, hosts world-class hypogene willemite deposits in dolomitic rocks interbedded with siliciclastic rocks deposited in subtidal to supratidal environments. Willemite ore bodies are structurally controlled along regional NE-trending structures which are interpreted as being active during the Neoproterozoic Brasiliano orogeny. The hydrothermal alteration is characterized by an early stage of Fe-dolomite, which replaced the host dolomitic rocks, followed by precipitation of minor sphalerite and then hematite and willemite. Elements commonly enriched in the zinc ore include As, Ba, Be, Bi, Cd, Co, Fe, Ge, In, Mo, Ni, Sb, Se, U, V and W. Mineralogical, fluid inclusion and isotopic data indicates that mixing of S-poor metalliferous saline fluids with meteoric water favored the formation of willemite ore. Carbonaceous phyllites from the underlying thick siliciclastic sequence show evidence of early enrichment in zinc (and ore-related metals) and remobilization, respectively, prior to and during the Brasiliano orogenic event. This unit is interpreted as a possible source of ore-related elements. It is proposed that during the Brasiliano orogeny, hot (T > 170 degrees C) saline fluids (>15 wt % eq. NaCl) leached metals from siliciclastic source rocks and precipitated willemite ore in the overlying dolomitic sequence along structures that favored mixing with oxidizing meteoric water

    A self-organizing map clustering approach to support territorial zoning

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    This work aims to evaluate three strategies for analyzing clusters of ordinal categorical data (thematic maps) to support the territorial zoning of the Alto Taquari basin, MS/MT. We evaluated a model-based method, another based on the segmentation of the multi-way contingency table, and the last one based on the transformation of ordinal data into intervals and subsequent analysis of clusters from a proposed method of segmentation of the Self-Organizing Map after the neural network training process. The results showed the adequacy of the methods based on the Self-Organizen Map and the segmentation of the contingency table, as these techniques generated unimodal clusters with distinguishable groups.Supported by National Council for Scientific and Technological Development –CNPq, Brazil, and by National Funds through the Portuguese funding agency, FCT -Fundação para a Ciência e a Tecnologia within project 2022.06822.PTDC. The work of Pedro Oliveira was also supported by the doctoral Grant PRT/BD/154311/2022 financed by the Portuguese Foundation for Science and Technology (FCT), and with funds from European Union, under MIT Portugal Progra

    Biological characterization of Bothrops marajoensis snake venom

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    This study describes the effects of Bothrops marajoensis venom (Marajó lancehead) on isolated neuromuscular preparations of chick biventer cervicis (CBC) and mouse phrenic nerve-diaphragm (PND). At low concentrations (1µg/ml for CBC and 5µg/ml for PND), the venom exhibited a neuromuscular blocking without any damaging effect on the muscle integrity. At higher concentration (20μg/ml for PND), together with the neuromuscular blockade, there was a moderate myonecrosis. The results show differences between mammalian and avian preparations in response to venom concentration; the avian preparation was more sensitive to venom neurotoxic effect than the mammalian preparation. The possible presynaptic mechanism underlying the neuromuscular blocking effect was reinforced by the observed increase in MEPPs at the same time (at 15min) when the facilitation of twitch tension occurred. These results indicate that the B. marajoensis venom produced neuromuscular blockade, which appeared to be presynaptic at low concentrations with a postsynaptic component at high concentrations, leading to muscle oedema. These observations demand the fractionation of the crude venom and characterization of its active components for a better understanding of its biological dynamics

    Differentiating irritable mood and disruptive behavior in adults

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    Introduction: Irritability has both mood and behavioral manifestations. These frequently co-occur, and it is unclear to what extent they are dissociable domains. We used confirmatory factor analysis and external validators to investigate the independence of mood and behavioral components of irritability. Methods: The sample comprised 246 patients (mean age 45 years; 63% female) from four outpatient programs (depression, anxiety, bipolar, and schizophrenia) at a tertiary hospital. A clinical instrument rated by trained clinicians was specifically designed to capture irritable mood and disruptive behavior dimensionally, as well as current categorical diagnoses i.e., intermittent explosive disorder (IED); oppositional defiant disorder (ODD); and an adaptation to diagnose disruptive mood dysregulation disorder (DMDD) in adults. Confirmatory factor analysis (CFA) was used to test the best fitting irritability models and regression analyses were used to investigate associations with external validators. Results: Irritable mood and disruptive behavior were both frequent, but diagnoses of disruptive syndromes were rare (IED, 8%; ODD, 2%; DMDD, 2%). A correlated model with two dimensions, and a bifactor model with one general dimension and two specific dimensions (mood and behavior) both had good fit indices. The correlated model had root mean square error of approximation (RMSEA) = 0.077, with 90% confidence interval (90%CI) = 0.071-0.083; comparative fit index (CFI) = 0.99; and Tucker-Lewis index (TLI) = 0.99, while the bifactor model had RMSEA = 0.041; CFI = 0.99; and TLI = 0.99 respectively). In the bifactor model, external validity for differentiation of the mood and behavioral components of irritability was also supported by associations between irritable mood and impairment and clinical measures of depression and mania, which were not associated with disruptive behavior. Conclusions: Psychometric and external validity data suggest both overlapping and specific features of the mood vs. disruptive behavior dimensions of irritability
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